Gas generator for pulverized fuel



April 3, 1934. w. B, PLUMMER GAS GENERATOR FOR PULVERIZED FUEL FiledJuly 27, 1928 y Snom/woz WILLIAM PLUMMER Patented Apr.` 3, 1934 UNITEDSTATES PATENT OFFICE GAS GENERATOR FOR PULVERIZED FUEL ,William B.Plummer, Jackson Heights, N. Y., as-

1 rsignor to Combustion Utilitiesl Corporation, New York, N. Y., acorporation of Maine Application July 27, 1928, Serial No. 295,721 14Claims. (ci. 1s-s3) This invention relates to the manufacture of fuelgas and more particularly to apparatus for converting large volumes ofilnely divided carbonaceous fuel into clean high quality producer 5 gas.1

The primary object of the present invention is to provide apparatus foreconomically and eiliciently gasifying relatively large amounts offinely divided fuel per unit volume of available gasmaking space.

" g Another object of the invention is to provide apparatus forcontinuously, rapidly and substantially completely converting nelydivided carbonaceous fuel into comparatively clean high quality producergas.

In any process for carbonizing and gasifying finely divided fuel thevelocity component of the gas formed in the direction of gas removal isone of the principal factors limiting the operating capacity of theapparatus employed for carrying out the process, for the reasons that asthis velocity component increases more and more fuel and solidimpurities are .carried out of the apparatus by entrainment in the.outgoing gas.

Accordingly, another object of the present invention is to provide novelmeans for gasifying nely divided carbonaceous fuel whereby a suitableregulation of the net velocity component of the gas formed in thedirection of its point of re- 30 moval toinhibit entrainment ofungasiiled fuel particles therewith can be effected without any seriousadverse effect on the gas-making capacity of the apparatus.

' Another object of the present invention is to provide means formaintaining controlled uniform or progressively increasing temperaturesin the direction of net gas and fuel movement through powdered fuelgasification equipment.

Another object of the invention is to provide means whereby the completeand continuous gasification of nely divided carbonaceous fuel can beeffected while simultaneously eliminating zones of excessive heat atpoints of fuel injection or elsewhere in the apparatus.

In accordance with this object, one feature of the inventioncontemplates effecting the gasication of finely divided fuel by means ofoxygen supplied to the gas'generator chiefly in combined form. Y

Withthe above and other objects and features in view the inventionconsists essentially in Y means whereby large volumes of finelyl dividedcarbonaceous fuel are continuously charged to and maintained inturbulent suspension in an upwardly directed relatively high velocityblast `a relatively low net velocity flow of fuel and gas formed in alateral direction towards a point of gas removal, and a resultantminimum entrainment of ungasiiled fuel particles and impurities with theproducer gas stream leaving'the gen- 4 erator.

' With these and other .objects and features in view, thel inventionconsists in the improved apparatusr for converting finely dividedcarbonaceous fuel into clean high quality producer gas which ishereinafter described and ymore particularly defined in the claims.

The various features of the invention are illustrated more or lessdiagrammatically in the accompanying drawing, in which:

Fig. 1 is a diagrammatic view in vertical elevation, with parts brokenaway, of a gas producer of the vtype exemplifying the preferred form ofthe present invention;

Fig. 21s a cross-sectional end view of thegas producer shown in Fig. 1taken on the line 2-2 of Fig. 1; e

Fig. 3 is.an enlarged view in vertical section of the upper portion ofone of the burners illustrated in Figs. 1 and 2.

The gas producer 10 which is illustrated in the accompanying drawing(see Figs. 1 and 2), consists essentially of a long relatively narrowwedgeshaped gasification chamber 12 having a roof or top closure 14andend and side walls 16 and 18l respectively. The roof and walls of thechamber 12 are preferably formed of or lined with refractory and heatinsulating material. The form of the gasification chamber 12 ispreferably that of a long upright wedge or horizontally disposedtrigonal chamber which is completely enclosed by an arched roof, end andside walls'except for a narrow opening lor throat 20 inthe base of thechamber 12 and at the pointv of the wedge. Opening 20 extends throughoutthe fulllength of the producer and connects the chamber 12 with anunderlying draft and ash or slag pit 22. A number of long narrow burnersor blast nozzles 24 are mounted end to end in pit 22 in positon toproject a blast or ame of air, steam and/or hot combustion supportinggases upwardly at high velocity into chamber 12 throughout its length.Each of the burners 24 in its preferred form consists of a relativelylong, narrow, centrally disposed mixing or blast chamber 26 surroundedby one or more annular chambers 28 and 30. Each of the burners 24isprovided with a long, narrow tip or nozzle 32 of refractory or otherhigh heat resistant material. Each tip 32 (see Fig. 3) has lateralopenings 34 in its walls whereby communication is establishedbetween acentral blast nozzle 36 and each 'of chambers 26, 28 and 30. Valved pipeconnections 38, 40 and.42 serve respectively to conduct air, steam,combustible gas, oxygen or other material for making up the blast to thecorresponding burner chambers 26, 28 and 30. The individual pipes 38, 40and 42 supplying each, of the burners are in turn supplied frommanifolds 44, 46 and 48 rimning lengthwise of the producer outside theproducer setting. A

Finely divided carbonaceous fuel such as coke, lignite or bituminouscoal, pitch or oil shale, is supplied to the producer through a fuelinlet4- 50 preferably located in an endwall of the producer near itstop. The fuel is conducted to the inlet /from a hopper or other source(not shown) by a screw conveyor 52 or equivalent feeding means, and isprojected from the inlet onto 'a cushion of combustion supporting gasesand flames directed upwardly from the burners 24 by means of a fiuid`charge side of the apparatus. A dust separator` is mounted in a main 62connecting the offtake 56 with the exhauster 58 for the purpose ofseparating and collecting any ash or slag particles which may be carriedout of the producer chamber by the generated gases. In the drawing arecuperator 64 has also been shown in the main 62 intermediate the otake56 and the exhauster 58: the function of the recuperator being to effectcontinuous heat interchange between the generated gases and air, steamor combustible gas being supplied to the burners 24. In the recuperatordesign illustrated the generated gases pass through inner tubes or flues66, and Vthe cooled gas normally exits fromv the recuperator through avalved oiftake 68. If desired part of the generated gas may exit fromthe recuperator through a valved connection 'I0 and be recycled by ablower y72 through a baied chamber 'I4 (surrounding tubes 66 and formingthe outer chamber of the recuperator) thence by a pipe '16 into manifold44, and thence back to the producer via connections 38 `and burners 24.In va case where none of the producer gas is utilized in making up theblast issuing from burners 24, air, steam or other gases used in makingup the blast'may be conducted to the blower '72 and the heating chamberof the recuperator by a valve pipe 78. l

The inside of the producer may be provided with one Aor more heatresistant baiiies or bridge walls (see Fig. 1), for causing the fuelcharged and gas formed to follow a sinuous path on its way towards theofftake 56. Likewise one or more secondary fuel inlets 82, supplied fromoverlying hoppers 84 controlled by feed gates 86, mayV be mounted inthev top of the producer to insure adequate fuel feeding capacity to theproducer and to provide sufficient secondary fuel to reduce the carbondioxide content of the DrQdilcer gas increase the CO content and caloricvalue of the final generated gas withdrawn through offtake 56.

VThe producer illustrated is designed particularly for operation as aslagging gas producer, the slope of the walls and material of which theyare composed being so chosen that the non-combustible solid componentsof the fuel undergoing gasification will flow or slide down the walls ofthe producer throughthe opening or throat 20 into the pit 22. If desireda flux such as lime may be introduced into the producer with the fuelcharge in order to effect suitable liquefaction and slagging of the ash.Fused slag may be removed from the pit 22 through a spout 88 (see Fig.2). In the design illustrated, however, provision is also made forquenching the slag with water or some other quenching medium. In theevent that it is desired to employ water as the quenching medium it maybe introduced through a pipe into the pit 22 and the quenched slag maybe removed from the pit through a spout 92 opening on the outside of theproducer structure, a water seal being in this case. maintained on pit22 and on slide gate 94. which can be elevated sulciently to eiectremoval of the quenched slag without -breaking the seal. -The burnertips 32 are demountable, and

several sets of these tips of varying wall thickness and nozzle capacityare preferably available so that by interchanging these tips a readieradjustment of capacity of each burner is afforded. In order to affordaccess to the pit 22 for cleaning and for changing burner tips andconnections, doors 96 are provided in one side of the pit 22 oppositeeach burner.

In operation finely divided fuel (with or without a flux for the ash)may be projected into the chamber 12 continuously in controlled amountsalong with a fluid carrier or vehicle such as air or hot producer gassupplied under pressure through the valved nozzle 54. The fuel thusprojected into the chamber 12 is prevented from settling on the sidewall of the producer prior to its complete gasification due to thecushion of hot gases` directed upwardly at high velocity into theproducer by burners 24. The fuel is maintained in a state of turbulentsuspension in the flames of hot gases issuing from burners 24 until itsgasification is complete. The ash residue of the fuel is fused by reasonof the high. temperatures developed and maintained in chamber 12, andthe thus fused ash settles on the sloping walls of the producer-andbuilds up into drops and uid streams which flow downwardly through thethroat 20 into the draft chamber and ash pit 22.

The producer illustrated has a length which is approximately four timesits mean breadth, and a height which is approximately twice its meanbreadth. The mean horizontal crosssectional area of the producer islarge, whereas the mean vertical cross-sectional area is relativelysmall. Likewise, as pointed out above, the mean cross-sectional area ofthe gas oitake 56 is relatively large. The invention contemplates aproducer'of the general design illustrated having a length which ispreferably three, or moretimes its mean breadth;l a height at leasttwice its mean breadth; a bottom blast opening 20 the width of which isabout one-third to onefth the mean breadth of the producer; and a gasyoitake 56 having a diameter preferably at least one-third the mean widthof the rproducer. By thus dimensioning the prducer and product ofprimary fuel combustion, and therebyby operating the exhauster 58 at acontrolled low speed thenet velocity flow of fuel and make gas throughthe producer in the direction of the oi'l'take 56 is kept at such a lowpoint as to inhibit entrainment of fuel particles in the gas at the timeit exits through the offtake. In operating a producer of the dimensionsillustrated and described, the ratio between the velocity of the blastentering the producer through opening 20 and the velocity of the exitgases leaving the producer through offtake 56 is preferably kept withina rangeA of from 2: 1 to 5:1 for best results. This velocity ratiovaries somewhat withthe degree of fineness of the fuel particles, withthe temperatures, and with the shape and dimensions of the producer.v Inthis connection a regulation is also maintained of the volume'of fuelinjected into the producer (by the valve 55 on nozzle 54) and of thevolume and velocity of combustion supporting lgases supplied by each ofthe burners 24. By adjustment of these various burner. and fuel supplyvalves, considerable flexibility in the degree of turbulence imparted tothe fuel held in suspension in the producer chamber may be obtainedwithout disturbing the adjustments whereby entrainment of unconsumedfuel with the outgoing make gases is avoided. By means of the valves inthe burner supply lines the composition. temperature and velocities ofthe cornhnstion supporting gases and flames projected into the producerchamber by each of the burners 24 are separately controlled.

'I'he thermaleiliciency of the process is increased by reason ofthemeans afforded for returning the sensible heat in the producer gas tothe producer in the form of preheated blast air, steam and recycledproducer gas or other` components of the blast, and also by reason ofthe means afforded for quenching the ash or slag if desired, the heatthus developed being returned to the producer in the form of make steam.

The invention contemplates proportioning the amounts of air or oxygen,combustible gas and steam supplied to the burners24, and the amounts offuel supplied through the primary and secondary fuel inlets, to maintainendothermic reactions leading to the reduction of C0: content and theproduction of a maximum CO content in the final make gas. This resultcan be obtained with a producer of the design illustrated withoutreducing the temperatures maintained in the producer below the tempera-It will be understood that the invention is not limited to the methodand apparatus herenbcfore illustrated and described, except insofar asit is dened in the claims. Thus for example combustion chambersseparated by heat resistan't partitions may beused in place of theburners 24 illustrated in the drawing, and a portion of the hot rawproducer gas may be recycled "to such burners or combustion chamberswithout being first passed through 'heat interchange apparatus.

The invention having been thus described, what is claimed as new is: 4

l. In vgas generating apparatus, the combination ofan horizontallyelongated upright wedgeshaped producer gas generating chamber, means forinjecting finely divided solid fuel and a fluid carrier therefor at acontrolled rate into one end of said chamber, means for directing hotcombustion-supporting gases at high velocity upwardly into saidchamber'through a narrow opening in.

ing finely divided solid fuel and a iluid carrier therefor atl acontrolled rate into one end of said Achamber, means for directing hotcombustionsupporting gases at high velocity upwardly into said chamberthrough a narrow opening in the base thereof, extending substantiallythe full length of the chamber, means for removing gases formed fromsaid chamber at a controlled slow rate through an oiftake in the end ofsaid chamber opposite the point of fuel injection, andmeansforintroducing a secondary supply of nelydivided fuel into said producerchamber in controlled amounts. Y

3. In gas generating apparatus, the combination of an elongated uprightwedge-shaped producer gas generating chamber, means for injecting nelydivided solid fuel and a fluid carrier therefore at a controlled rateinto one end of said chamber, means for directing hotcombustionsupporting gases at high'velocity upwardly into said chamberthrough a narrow opening in the base thereof, means for removing thegenerated producer gas formed from said chamber at a controlled slowrate through an offtake in' the end of said chamber opposite the pointof fuel injection, a heat recuperator in a gas main leading oil.' fromsaid gas offtake, and means for recycling a portion of the generated gasin heat interchanging relationship with the main body of gas removedthrough said offtake and thence into theA producer through saiddirecting means.

4. In a gas generating apparatus, the combination of an elongatedupright-wedge-shaped producer gas generating chamber, means forinjecting finely divided solid fuel and a uid carrier therefor at acontrolled rate into one end of said chamber, means f or directing hotcombustionsupportng gases at high velocity upwardly into said chamberthrough a narrow opening in the basethereof, means for removing thegenerated producer gas formed from said chamber at a controlled slowrate through an offtake in the ena of said chamber opposite the point offuel injection, and means for preheating the combustion supporting gasesby heat interchange with the generated gas removed through saidoiitake.4

5. In gas generating apparatus, the combination of an elongated uprightwedge-shaped producer gas generating chamber, means for injecting finelydivided solid fuel and a fluid carrier therefor at a controlled rateinto one end of said chamber, means for directing hotcombustion-supporting gases at high velocity upriertherefor at acontrolled rate into one end of said chamber, a draft chamber and ashpit immediately below said chamber connected therewith by a narrow blastthroat extending the full length of the producer chamber, a plurality ofgas burners mounted end to. end in said draft chamber in position todirect flames of combustion-supporting gases upwardly at high velocityinto said producer, separate means vfor supplying hot combustible gas,air and steam to each of said burners in controlled amounts, a gasoiftake of relatively largel cross-sectional area in the end of saidproducer opposite the point of fuel injection, and means for supplying afluid ashquenching medium to said ash pit.

7. In gas generating apparatus, the combination of an elongatedwedge-shaped producer gas generating chamber having end walls andhorizontally elongated steep downwardly-converging opposite side walls,means in an end wall for pro- :lecting finely divided solid fuel andfluid into the chamber and longitudinally thereof, means in the oppositeend wall for removing from the chamber the producer gas generated, thebase of the said chamber being provided with a narrow restricted throatextending substantially throughout its length, andmeans disposed belowthe said throat and adapted for directing aligned high velocity streamof hot combustion-supporting gases upwardly into the said chambersubstantially,Y throughout the length of the said throat.

8. In gas generating apparatus, the combination of an elongatedwedge-shaped producer gas generating chamber having end walls and steep,downwardly-converging opposite side walls, the said chamber having alength approximately three times its mean breadth and a heightapproximately twice its mean'breadth, means in an end wall forprojecting finely divided solid fuel and fluid into the chamber, meansin the opposite end wall for removing from the chamber the producer gasgenerated, the base of the said chamber being provided with a 4narrowrestricted throat extending substantially throughout its length, andmeans disposed below the said throat and adapted for directing a highvelocity stream of hot combustion-supporting gases upwardly into the said chamber substantially throughout the length of the said throat. c i

9. Gas generating apparatus, comprising a horizontally-disposedelongated gasification cham- Y ber of V-shaped transverseverticalsection,l means for projectingnely divided solid` fuel into thevsaid chamber longitudinally thereofthrough the upper portion of an endwall, means in the upper portion of the opposite end wall for laterallyre- 'moving from the chamber the producer I gas formed therein, thebaseof the chamber being Atherewith through the said throat, and means inthe said closed chamber and adapted to project upwardly at high velocitya longitudinally-ehm. gated sheet of hot combustion-supporting gasesinto the gasification chamber through the said throat. Y

10. Gas generating apparatus, comprising a horizontally-elongated retorthaving end walls and steeply sloping side walls, the said retort havinga vertical mid-portion constrieted to form a throat extendingsubstantially the length of the retort and establishing communicationbetween an upper gas generating. chamber and a lower burner chamber,means in the burner chamber adapted to direct a high velocity stream ofhot combustion-supporting gases of preselected composition andtemperature upwardly through the said throat along substantially itsentire length, means in one end of the gas generating chamber adapted toproject finely divided solid fuel into the same, and means for removingfrom the upper part of the opposite end wall of the gas generatingchamber the producer gas generated.

1l. Gas generating apparatus, comprising a horizontally-elongated retorthaving end walls and steeply sloping side walls, the said retort havinga vertical mid-portion constrieted to form a throat extendingsubstantially the length of the retort and establishing communicationbetween an upper gas generating chamber and a lower burner chamber,means in the burner chamber adapted to direct a high velocity stream ofhotcombustion-supporting gases of preselected composition andtemperature upwardly through the said throat along its entire length,lmeans for controlling the temperature, composition and velocity of thestream of combustion supporting gases, means in one end of the .gasgenerating chamber adapted to project finely divided fuel into the same,and means for removing from the upper part of ythe opposite end wall ofthe gas generating chamber the producer gas generated.

12. Gas generating apparatus having in combination, an elongated gasgenerating chamber having end walls, steep downwardly converging sidewalls, means for introducing finely divided solid fuel'laterally intothe chamber through an end wall, means for removing generated gaseslaterally from the chamber through the upper por-- tion of the oppositeend wall, a burner chamber disposed below theV gas generating chamberand in communication with the latter through an elongated narrowpassageway, means disposed in the burner chamber adapted for directing ahigh velocity stream of hot combustion-supporting gases upwardly throughthe throat and into the gas generating chamber substantially throughout130 the length of the latter, and baille means depending from the top'ofthe gas generating chamber and interposed between the solid fuelintroducing means and the said generated gas removing means. y

13. In gas generating apparatus, the combination of ahorizontally-elongated wedgey-shaped producer gas generating chamber,means for injecting finely divided solid fuel and a fiuid carriertherefor at a controlled rate into one end of 140 the said chamber, adraft chamber and ash pit disposed immediately below the gas generatingchamber and connected therewith by a constricted narrow blast throatextending substan-l tially throughout the length of the said chamber,145 a plurality of vertically-disposed long narrow v lburners mountedend to end-in the said draft chamber, each of the burners being adaptedto direct a high velocity stream of combustion-supporting gases upwardlythrough the narrow throat and into the gas generating chamber through aseparate portion of the throat, and independent valve-controlled meansconnecting each burner respectively with a source of air, a source ofsteam and a source of a combustible gas,

and a gas otake of relatively large cross-sectional area in the end Wallof the gas generating chamber opposite that having the solid fuelinjection means. v y

14. In gas generating apparatus, the combination of ahorizontally-elongated wedge-shaped producer gas generating chamber,means for injecting finely divided solid fuel and a fluid carriertherefor at a controlled rate into one end of the said chamber, a draftchamber and ash pit disposed immediately below the gas generatingchamber and connected therewith by a constricted narrow blast throatextending substantially throughout the length of the said chamber, aplurality of vertically-disposed long narrow burners mounted end to endin thesaid draft chamber, a refractory burner tip having lateralopenings mounted on each burner, each of the burners being adapted todirect a highvelocity stream of combustion-supporting gases upwardlythrough the narrow throat and into the gas generating chamber through aseparate portion of the throat, and independent valve-controlled meansconnecting each burner respectively with a source of air, a source ofsteam and a source of a combustible gas, and a gas offtake of relativelylarge cross-sectional area in the end lwall of the gas generatingchamber opposite thatv having the solid fuel injection means.

WILLIAM B. PLUMmxR.

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